WO2002051756A2

WO2002051756A2 - Method and conditioning agent for treating waste water and air pollutants

Info

Publication number: WO2002051756A2
Application number: PCT/DE2001/004784
Authority: WO
Inventors: Christian Uphoff
Original assignee: Georg Fritzmeier Gmbh & Co.
Priority date: 2000-12-27
Filing date: 2001-12-19
Publication date: 2002-07-04
Also published as: ATE280136T1; EP1351895A2; PT1351895E; US6837998B2; WO2002051756A3; ES2231566T3; US20040058430A1; WO2002051756B1; EP1351895B1

Abstract

The invention relates to a conditioning agent for treating waste water and to a method for producing a conditioning agent of this type, which contains a proportion of flocculants or precipitants containing polymers and a proportion of micro-organisms.

Description

description

Process and conditioning agent for the treatment of waste water and air pollutants

The invention relates to a method and a conditioning agent for the treatment of waste water and air pollutants.

In biological wastewater treatment, microorganisms convert the organically usable ingredients of the wastewater to be processed into cell material or gases, such as C0 ₂ , methane, hydrogen sulfide and others. Depending on the process control, a distinction is made between aerobic and anaerobic processes, whereby the more manageable aerobic processes are generally used in municipal wastewater treatment plants. In such wastewater treatment plants, mechanical clarification is followed by biodegradation in an activated sludge basin in which the carrier of the biological purification, ie the sludge activated with microorganisms, is accommodated. Air is introduced into this activated sludge tank and the oxygen required for biological conversion is thus supplied. This aeration of the wastewater in the activated sludge or aeration basin forms slimy, macroscopically recognizable flakes, which settle as soil sludge when the aeration is ended.

According to the publication www.uni-pots- damm.de/u/putz/oktober 1996 / 30.htm, organic or inorganic polymers that support flake growth are added to the wastewater to increase the efficiency of the biological conversion. The polymers are designed in such a way that flakes which are as compact and dense as possible and have a slightly fissured surface are formed, which are combined to form larger flake groups and are therefore insensitive to the effects of shear forces from the waste water flow.

Such flocculants are polymers with different charge densities, charge distributions and molecule sizes depending on the task. They are used for the separation of solids from suspensions with organic or inorganic particles, which can be distributed up to the colloidal consistency. Due to the high adsorption potential, flocculation aids act as a link between the solid particles and the microflakes created by the use of flocculants, which are aggregated into larger flakes (flocculation).

In addition to the polymers that act as flocculants, the conditioning agent can also contain precipitants and flocculants. In wastewater treatment, AI or Fe salts are often used as flocculants, which form flake-like precipitates with a very large surface area in certain pH ranges. Heavy metals or other undesirable wastewater constituents can be adsorbed on these flakes. Monomeric salts, for example of aluminum, calcium, iron and magnesium or polymeric aluminum or iron compounds, are used as precipitants in wastewater treatment.

Despite considerable progress in polymer chemistry, the existing conditioning agents can only be designed for an average composition of the wastewater to be treated, whereby it is particularly important when there are fluctuations in the biosphere, i.e. of the proportion of organic matter in the wastewater to be treated may mean that the biological implementation does not meet the requirements.

In contrast, the invention has for its object to provide a conditioning agent and a method for treating waste water and air pollutants by one largely independent of fluctuations in the wastewater treatment existing in the biosphere.

This object is achieved by a conditioning agent according to claim 1, a method with the features of claim 10 and a use of the conditioning agent according to claim 15.

According to the invention, the conditioning agent contains a predetermined proportion of microorganisms, so that the biological activity is essentially determined by the microbiotic mixed cultures contained in the conditioning agent and is therefore largely independent of the random composition of the microorganisms contained in the waste water or air. As will be described in more detail below, when the conditioning agent containing the polymers and microorganisms is introduced, a stable biofilm is formed on the surface of the flakes formed on the polymers and is not destroyed even when the wastewater is highly turbulent. In this way, immobilization of the microorganisms is achieved with reference to the flake, so that ideal conditions for the biological implementation are largely created.

It was surprisingly shown that the conditioning agent can also be used for cleaning air laden with pollutants.

In a particularly preferred exemplary embodiment, the conditioning agent contains a microbiotic mixed culture which contains a proportion of photosynthetically active microorganisms and a proportion of luminous bacteria in a biological solution.

As mentioned at the beginning, biopolymers and other organic or inorganic polymers are used as flocculants. In recent times, so-called Conjugated polymers Attention, which release light when binding a certain substance. Conjugated polymers consist of semiconductor materials and have so far been used primarily for physical and technical purposes, for example for solar cells or flat screens. The luminescence of these semiconducting polymers can be used to completely or partially replace the luminous bacteria of the mixed microbiotic culture.

The handling and storage of the conditioning agent is particularly simple if the microorganisms are frozen or freeze-dried for storage, the process conditions during cooling having to be selected such that the microorganisms are not damaged.

With regard to the composition of the mixed microbiotic culture, for the sake of simplicity, reference is made to the applicant's older patent application DE 100 62 812, the content of which is to be included in the disclosure of the present patent application.

Other advantageous developments of the invention are the subject of the further subclaims.

Preferred exemplary embodiments of the invention are explained in more detail below with reference to drawings. Show it:

1 shows a block diagram of a method for the biological treatment of waste water and

Figure 2 is a schematic diagram of a flake formation according to the invention.

A method for the biological treatment of wastewater (municipal, industrial wastewater) is described below with the aid of FIG Flake growth is mixed with a conditioning agent in the wastewater, which contains a proportion of flocculant and / or precipitant as well as precipitation aids, for example organic or inorganic and also conjugated polymers. Such flocculants and precipitants are substances which cause the suspended particles to agglomerate in the wastewater and, through the enlargement of the particles, enable the solid to be separated from the liquid phase more quickly. In addition to the polymers, this conditioning agent can also contain further constituents, such as, for example, metals and other constituents which support flaking. According to the invention, the conditioning agent contains microbiotic mixed cultures in a defined composition, by which the metabolic reactions in the flake are essentially determined.

According to the attached process scheme, the microbiotic mixed culture (microbiological composition) contains, in a preferred embodiment, a proportion of photosynthetically working microorganisms 1, a proportion of luminous bacteria or light-emitting microorganisms 2 with a similar effect, which are dissolved in a broadband biological solution 4. As mentioned at the beginning, some of the light-emitting microorganisms can be replaced by conjugated polymers which emit light in the presence of certain biomolecules in the microbiological composition.

The interplay between the photosynthetically active microorganisms and the luminescent bacteria or the conjugated polymers means that the photosynthetically active microorganisms are stimulated to photosynthesis by the emitted light. The microorganisms carry out photosynthesis with hydrogen sulfide and water as starting material and release sulfur or oxygen. They can also bind nitrogen and phosphate and break down organic and inorganic matter.

Photosynthetically active microorganisms which are optionally phototrophic are preferably used in the microbiological composition according to the invention. Phototrophic facultative means that the microorganisms can grow both under anaerobic conditions in the light and under aerobic conditions in the dark.

Photosynthetic bacteria include gram-negative aerobic rod-shaped and circular bacteria as well as gram-positive circular bacteria. These can have endospores or be present without spores. This includes, for example, gram-positive actinomycetes and related bacteria.

In this context, nitrogen-binding organisms can also be mentioned. These include, for example, algae, such as Anabena Nostoc in symbiosis with Azola. Furthermore actinomycetes, e.g. Frankia in symbiosis with alder and bacteria, such as Rhizobium in symbiosis with legumes.

Aerobic algae, Azotobacter, methane oxidizing bacteria and sulfur bacteria can also be used. This also includes green sulfur bacteria and brown-green photosynthesis bacteria. Violet sulfur bacteria and violet sulfur bacteria cannot be mentioned here either.

It is preferred that the microbiological composition according to the invention contains optional phototrophic microorganisms, prochlorophytes, cyanobacteria, green sulfur bacteria, purple bacteria, chloroflexus-like forms and heliobacterium and heliobacillus-like forms. The aforementioned optional phototrophic Microorganisms can also be present as mixtures of two or more of them. In a very special embodiment, all six of the microorganisms mentioned are present as a mixture.

The light that drives photosynthesis comes from the luminous bacteria that are included as a second essential component in the microbiological composition of the present invention. These luminous bacteria have a luminosity, i.e. they are able to emit light quanta. It is a system that works enzymatically. The luciferin-luciferase system can be mentioned here as an example.

In a preferred embodiment, the mixture according to the invention contains Photobacterium phosphoreum, Vibrio fischeri, Vibrio harveyi, Pseudomonas lucifera or Beneckea as luminous bacteria. It is also possible to choose a mixture of at least two of them.

To optimize the microbiological composition according to the invention, further constituents can be contained therein. Such secondary components are preferably plant extracts, enzymes, trace elements, polysaccharides, alginate derivatives, other microorganisms as above. The secondary components can be present individually or in combination in the microbiological composition according to the invention. The plant extracts can contain, for example, plantain.

As a nutrient solution for the microbiological composition according to the invention, a solution is generally used which contributes to the fact that the constituents contained therein, in particular the microorganisms, can live in it without further ado. It is particularly important that the interaction of the photosynthetic bacteria and the luminous bacteria is fully effective. It has It has been shown that a biological nutrient solution with molasses, in particular raw sugar molasses or sugar beet molasses, is suitable as the main component.

The photosynthetic microorganisms and the luminescent bacteria are usually present in the microbiological composition according to the invention in a ratio of 1:10 to 1: 500. A preferred ratio is 1: 100.

The above-described components are homogenized so that a microbiotic culture 6 is present as the first intermediate product of the method according to the invention, the proportions of which are adjusted as a function of the waste water to be treated.

In a subsequent process step 8, the mixture is deep-frozen and, if necessary, freeze-dried in vacuo, so that the solvent, in the present case for example water components, is evaporated in the frozen state (sublimation drying). Such dehydration is a widely used method for the gentle drying and preservation of sensitive goods. The drying parameters are set so that the microorganisms are not damaged. Preliminary tests showed that a cooling rate of more than 30 ° C. per minute, preferably about 40 ° C. per minute or faster, is optimal in order to prevent damage to the microorganisms.

Through this drying step, the extracellular polymeric substances (EPS) surrounding the cells of the microorganisms are dehydrated, so that the slimy EPS layer is thickened and forms a protective layer which protects the microorganisms during the freezing process. The dehydrated product 9 obtained is then mixed in a mixing stage 12 with a flocculant or precipitant containing the polymers, and this mixture is added at a predetermined concentration to an aeration tank 14 containing wastewater to be cleaned. Before being mixed with the flocculant or precipitant 10, the drying / freezing material is built up under negative pressure, a negative pressure of 0.01 millibars having proven to be advantageous in the first preliminary tests.

Oxygen is blown into the activated sludge basin, whereby the process engineering task is to distribute the oxygen as evenly as possible and to keep the resulting flakes in suspension, so that a large and evenly distributed mass transfer area and sufficient oxygen is made available for biological conversion ,

The polymers introduced into the wastewater form long chains with a positive surface charge, on which the organic suspended solids, which usually have a negative surface charge, are attached - this creates a germ cell for a flake, the growth of which depends, among other things, on the type of flocculant , the activity of the microorganisms and the composition of the wastewater.

The conditioning agent according to the invention acts as a flocculant with which substances dissolved or distributed in a nebiform form in a waste water or a gas can be drawn off by inclusion flocculation. The basic mechanism of this inclusion flocculation is shown in FIG. 2. The thread-like cationic polyelectrolytes are formed, for example, by proton-releasing archaea and added charge carriers, while the anionic polyelectrolytes by ion-releasing bacteria and the negative charge environment in the wastewater or the loaded one Air will be made available. In particular, the protons releasing microorganisms present in the mixture attach to the sediments present in the waste water. These colloid particles are then trapped between the cationic and anionic polyelectrolytes, as shown in Fig. 2, and agglomerated into macro flakes. The flake which forms thus serves as a carrier for the microorganisms which accumulate in and on the flakes and colloid particles. It binds nutrients that are available to the microorganisms in and on the flake for their growth. In certain applications, it may be advantageous if the polymers and / or microorganisms are added continuously.

In the exemplary embodiment described with reference to FIG. 1, the conditioning agent was used to treat waste water.

Another area of application of the conditioning agent according to the invention is in the cleaning of air or other gaseous substances laden with particulate pollutants. This problem is explained using a concrete example.

Until the 1960s, tar adhesives, which were produced on the basis of coal tar pitch or bitumen, were usually used to lay cork boards in the industrial sector. When laying the cork boards, these hot glues were poured directly onto the cork boards and then pressed against the walls, ceilings and on the floor. To date, tar or bituminous adhesives are also used in the laying of wooden paving in commercial and industrial areas.

These tar adhesives have not been produced in Germany since the mid-1970s and have to be used for them Purposes imported from abroad. The cessation of the production of tar adhesives in Germany was voluntary, since technically mature, harmless replacement products are now available.

When demolishing or converting buildings in which materials glued with tar adhesives have been processed, there can be a considerable health risk for the people involved in the demolition, since the tar adhesives contain extremely high concentrations of polycyclic aromatic hydrocarbons (PAHs). For occupational safety reasons, suitable precautions must be taken to rule out health hazards due to dust emissions and direct skin contact. This means that only specialist companies may be used, whereby working methods with effective dust extraction that are as dust-free as possible should be selected. In order to minimize the development of dust when the contaminated components break out, adequate moisture nebulization (moistening) must be provided. It was surprisingly found that by adding the conditioning agent according to the invention to the humidifying agent (water), the PAH concentration in the air can be significantly reduced compared to conventional solutions, so that the health risk when dismantling such contaminated buildings can be reduced with comparatively little effort. Due to the cationic polyelectrolyte contained in the conditioning agent according to the invention, the released PAH particles are again combined into a kind of flake and bound to the original substance.

As already mentioned above, microbial biopolymers can also be used in the conditioning agent according to the invention instead of synthetic polymers. For example, a significant increase in efficiency can be achieved by adding chitin, which, along with cellulose, is the most common natural before biopolymer is. Here, microbial, biochemical degradation of crustacean chitin chitosan is obtained enzymatically. Chitosan has a positive ionic charge and can therefore bind the negatively charged components in the waste water or in the exhaust air. The biopolymers that can be used with the conditioning agent can consist of a mixture and can be produced from waste materials from the sugar-producing industry. The biopolymer is easily water soluble with a very high reactivity.

The microorganisms contained in the conditioning agent according to the invention are selected such that when a flake is formed, a slimy extracellular polymeric substance (EPS) is produced in which a number of bacterial cells are embedded. This slime formation, particularly on the surface of the flake, forms a type of protective shield against toxic substances (for example heavy metals) which prevents these substances from penetrating into the cell interior. The EPS can also act as a support structure for filamentally growing types of bacteria. Another effect of the EPS is that it acts as a diffusion barrier that prevents the diffusion of substances required for the implementation, such as exoenzymes. Furthermore, bacteria that live in symbiosis with other species use the EPS as a means of being able to stay in close proximity to these bacteria.

The composition of the conditioning agent is selected so that the flakes formed are surrounded by a complete EPS layer, so that the degradation and conversion reactions can be carried out with an extremely high degree of efficiency. The organic matter of the supplied wastewater or the loaded exhaust air to be cleaned is adsorbed and oxidized by the flake or built up to new cell substance, whereby part of the flake is consumed itself. The photosynthesis described at the beginning takes place within the flake, so that it acts as a macroscopic "photobioreactor".

In the first experiments, good results were achieved with a mixture consisting of ten parts by volume of dissolved microorganisms on one part by volume of polymer. The microbiological solution can contain about two percent by volume of microorganisms.

Another advantage of the conditioning agent according to the invention is that the long polymer chains are cracked by the microorganisms, so that the further processing of the activated sludge is simplified. In existing plants, the long-chain polymers often posed a significant procedural problem in the further treatment of the sludge. Due to the improved biological implementation, the activated sludge can be broken down in the digester much faster than with previously known processes.

Disclosed is a conditioning agent for the treatment of waste water and waste air, a method for producing such a conditioning agent and a use of the conditioning agent which contains a proportion of polymers (biopolymers, conjugated polymers, other organic or inorganic polymers) and a proportion of flocculants or precipitants Contains microorganisms.

Claims

claims

1. Conditioning agent for the treatment of wastewater or laden air, with a proportion of polymers which support flaking or precipitation, characterized by a proportion consisting of a microbiotic mixed culture.

2. Conditioning agent according to claim 2, wherein the mixed culture contains photosynthetic microorganisms and luminous bacteria in a biological solution.

3. Conditioning agent according to claim 2 or 3, wherein the mixed culture is frozen or freeze-dried before mixing with the polymers.

4. Conditioning agent according to claim 2 or 3, wherein in the mixture as optional phototrophic microorganisms, prochlorophytes, cyanobacteria, green sulfur bacteria,

Purple bacteria, chloroflexus-like forms and heliobacterium and heliobacillus-like forms as well as mixtures of two or more thereof are contained.

5. Conditioning agent according to one of claims 2 to 4, wherein the mixture contains as luminous bacteria Photobacterium phosphoreum, Vibrio fischeri, Vibrio harveyi, Pseudomonas lucifera or Beneckea or mixtures of at least two of them.

6. Conditioning agent according to at least one of claims 2 to 5, wherein it further contains, as minor components, plant extracts, enzymes, trace elements, polysaccharides, alginine derivatives, other microorganisms, either individually or in combination.

7. Conditioning agent according to one of the preceding claims 2 to 6, wherein for 10 volume parts of mixed culture (microorganism plus solution) is a volume fraction of flocculant.

8. Conditioning agent according to one of the preceding claims, wherein the polymer is a conjugated polymer.

9. Conditioning agent according to one of claims 1 to 7, wherein the conditioning agent contains biopolymers.

10. A method for producing a conditioning agent for the biological treatment of waste water, comprising the steps:

Producing a polymer or a polymer mixture acting as a flocculant or precipitant; - Preparation of a microbiotic mixed culture with microorganisms in a biological solution; - Mixing the mixed culture with the polymer mixture.

11. The method according to claim 10, wherein the mixed culture is frozen or freeze-dried.

12. The method according to claim 10 or 11, wherein the mixed culture is cooled to a temperature below -50 ° C.

13. The method according to any one of claims 10 to 12, wherein the mixed culture is thawed before mixing with the polymer mixture - preferably at a negative pressure.

14. The method according to any one of claims 8 to 13, wherein the mixed culture forms a biofilm when the conditioning agent is introduced into wastewater on the surface of a flake formed on the polymers.

15. Use of a conditioning agent according to one of claims 1 to 9 for binding particulate air pollutants.

16. Use according to claim 1, wherein the conditioning agent is added to a moistening agent that is sprayed like a mist.